# US 2010/0163586 A1 · Stopper structure and production method therefor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0163586 A1 - Document ID: US20100163586A1 - Status: Published application - Kind: A1 - Application number: 12/524,962 - Filed: 2008-02-05 - Published: 2010-07-01 - Earliest claimed: 2007-02-07 - Assignees: Krosakiharima Corporation - Inventors: Junichi Funato; Takahiro Azuma - Web page: https://patentgrep.com/patent/US20100163586A1 ## CPC - B22D 41/186: {with means for injecting a fluid into the melt} - B22D 41/18: Stopper-rods therefor - B22D: CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES (shaping of plastics or substances in a plastic state B29C; metallurgical processing, selection of substances to be added to metal C21, C22) ## Abstract The present invention provides a stopper structure capable of preventing loosening of a shaft rod during use, and gas leakage which is likely to occur when the stopper structure is designed to allow gas to pass therethrough. The shaft rod 1 is adapted to be mounted in a mounting hole 2a of a refractory stopper 2, and formed to have an outer peripheral surface including a first tapered sub-surface 4a which increases in diameter toward an axially lower edge of the shaft rod. The mounting hole 2a of the refractory stopper 2 is formed to have an inner surface including a second tapered sub-surface 4b adapted to come into surface contact with the first tapered sub-surface 4a. The shaft rod 1 is adapted to be fastened to the refractory stopper so as to allow the first tapered sub-surface 4a to be brought into close surface contact with the second tapered sub-surface 4b. The distal end of the shaft rod 1 is formed in a configuration satisfying the following relation: tan θ≦D/2A, wherein: A is a length of the shaft rod 1 between a position of the shaft rod 1 corresponding to an upper edge surface 2S of the refractory stopper, and a start position of the first tapered sub-surface 4a; D is an outer diameter of the first tapered sub-surface 4a at the start position; and θ is a taper angle of the first tapered sub-surface 4a. ## Claims ### Claim 1 A stopper structure comprising a refractory stopper, and a shaft rod for connecting said refractory stopper to a drive unit, said shaft rod having a distal end mounted in a mounting hole of said refractory stopper, wherein: said distal end of said shaft rod has an outer peripheral surface including a first tapered sub-surface which increases in diameter toward an axially lower edge of said shaft rod; said mounting hole of said refractory stopper has an inner surface including a second tapered sub-surface adapted to come into surface contact with said first tapered sub-surface; and said shaft rod is adapted to be movably fastened to said refractory stopper so as to allow said first tapered sub-surface to be brought into close surface contact with said second tapered sub-surface, said shaft rod being designed to satisfy the following formula (1): tan θ≦D/2A (1) , wherein: A is a length of said shaft rod between a position of said shaft rod corresponding to an upper edge surface of said refractory stopper, and a start position of said first tapered sub-surface; D is an outer diameter of said first tapered sub-surface at said start position; and θ is a taper angle of said first tapered sub-surface. ### Claim 2 (depends on 1) The stopper structure as defined in claim 1, wherein said shaft rod has a threaded portion in an outer peripheral surface thereof at a position above said upper edge surface of said refractory stopper, and wherein said stopper structure further comprises a seat plate adapted to be threadingly engaged with said threaded portion of said shaft rod, and screwed toward said upper edge surface of said refractory stopper so as to allow said shaft rod to be fixedly fastened to said refractory stopper. ### Claim 3 (depends on 1) The stopper structure as defined in claim 1, wherein said shaft rod has a threaded portion in an outer peripheral surface thereof at a position above said upper edge surface of said refractory stopper, and wherein said stopper structure further comprises: a seat plate adapted to be threadingly engaged with said threaded portion of said shaft rod, and screwed toward said upper edge surface of said refractory stopper so as to allow said shaft rod to be fixedly fastened to said refractory stopper; and a sealing material provided between a lower surface of said seat plate and said upper edge surface of said refractory stopper. ### Claim 4 (depends on 1) The stopper structure as defined in claim 1, wherein said shaft rod includes a first shaft rod segment having said distal end adapted to be mounted in said mounting hole of said refractory stopper, and a second shaft rod segment threadingly engageable with a threaded portion formed in an outer peripheral surface of said first shaft rod segment at a position above said upper edge surface of said refractory stopper, said second shaft rod segment being adapted, in a state after being threadingly engaged with said threaded portion of said first shaft rod segment, to be screwed toward said upper edge surface of said refractory stopper so as to allow said first shaft rod segment to be fixedly fastened to said refractory stopper. ### Claim 5 (depends on 1) The stopper structure as defined in claim 1, wherein said shaft rod includes a first shaft rod segment having said distal end adapted to be mounted in said mounting hole of said refractory stopper, and a second shaft rod segment threadingly engageable with a threaded portion formed in an outer peripheral surface of said first shaft rod segment at a position above said upper edge surface of said refractory stopper, said second shaft rod segment being adapted, in a state after being threadingly engaged with said threaded portion of said first shaft rod segment, to be screwed toward said upper edge surface of said refractory stopper so as to allow said first shaft rod segment to be fixedly fastened to said refractory stopper, and wherein said stopper structure further comprised a sealing material provided between a lower edge surface of said second shaft rod segment and said upper edge surface of said refractory stopper. ### Claim 6 (depends on 1) The stopper structure as defined in claim 1, wherein said shaft rod includes a first shaft rod segment having said distal end adapted to be mounted in said mounting hole of said refractory stopper, and a second shaft rod segment adapted to be fitted onto said first shaft rod segment and attached to said first shaft rod segment by means of a fingertip connector mechanism, said second shaft rod segment being adapted, when it is attached to said first shaft rod segment by means of said fingertip connector mechanism, to be fixedly pressed against said upper edge surface of said refractory stopper so as to allow said first shaft rod segment to be fixedly fastened to said refractory stopper. ### Claim 7 (depends on 1) The stopper structure as defined in claim 1, wherein said shaft rod includes a first shaft rod segment having said distal end adapted to be mounted in said mounting hole of said refractory stopper, and a second shaft rod segment adapted to be fitted onto said first shaft rod segment and attached to said first shaft rod segment by means of a fingertip connector mechanism, said second shaft rod segment being adapted, when it is attached to said first shaft rod segment by means of said fingertip connector mechanism, to be fixedly pressed against said upper edge surface of said refractory stopper so as to allow said first shaft rod segment to be fixedly fastened to said refractory stopper, and wherein said stopper structure further comprised a sealing material provided between a lower edge surface of said second shaft rod segment and said upper edge surface of said refractory stopper. ### Claim 8 (depends on 1) The stopper structure as defined in claim 1, wherein said shaft rod has an internal space adapted to allow gas to pass therethrough, and communicated with said mounting hole of said refractory stopper or a hole of said refractory stopper penetratingly extending to a distal end thereof ### Claim 9 (depends on 1) A method of producing the stopper structure as defined in claim 1, comprising the steps of: setting said distal end of said shaft rod at a given position in a mold for forming said refractory stopper; charging a refractory mixture (ingredients) around said distal end of said shaft rod in said mold; applying pressure on said refractory mixture (ingredients) in said mold to form said refractory stopper in a manner combined with said distal end of said shaft rod; and subjecting said obtained molded product to burning. ### Claim 10 (depends on 2) The stopper structure as defined in claim 2, wherein said shaft rod has an internal space adapted to allow gas to pass therethrough, and communicated with said mounting hole of said refractory stopper or a hole of said refractory stopper penetratingly extending to a distal end thereof ### Claim 11 (depends on 3) The stopper structure as defined in claim 3, wherein said shaft rod has an internal space adapted to allow gas to pass therethrough, and communicated with said mounting hole of said refractory stopper or a hole of said refractory stopper penetratingly extending to a distal end thereof ### Claim 12 (depends on 4) The stopper structure as defined in claim 4, wherein said shaft rod has an internal space adapted to allow gas to pass therethrough, and communicated with said mounting hole of said refractory stopper or a hole of said refractory stopper penetratingly extending to a distal end thereof ### Claim 13 (depends on 5) The stopper structure as defined in claim 5, wherein said shaft rod has an internal space adapted to allow gas to pass therethrough, and communicated with said mounting hole of said refractory stopper or a hole of said refractory stopper penetratingly extending to a distal end thereof ### Claim 14 (depends on 6) The stopper structure as defined in claim 6, wherein said shaft rod has an internal space adapted to allow gas to pass therethrough, and communicated with said mounting hole of said refractory stopper or a hole of said refractory stopper penetratingly extending to a distal end thereof. ### Claim 15 (depends on 7) The stopper structure as defined in claim 7, wherein said shaft rod has an internal space adapted to allow gas to pass therethrough, and communicated with said mounting hole of said refractory stopper or a hole of said refractory stopper penetratingly extending to a distal end thereof.